Pneumatic fluid elevating device



C. D. RUBEL PNEUIATIC FLUID EI-JEVATING DEVICE Nqv. 21, 1933.

Filed June 12, 1930 5 Sheets-Sheet lv I N VEN 7 0R. C. p. Pub el ATTORNEYJ -NUWWWNIIWI l n l NOV. 2l, 1933. C' D RUBEL PNEUMATIC FLUIDELEVATING DEVICE Nov. 2l, 1933. c. D. RUBEL PNEUMATIC FLUID ELEVATINGDEVICE 5 sheets-sheet 5 R. ,w ,m M A R lj W'L m NP T W /Q D C Yf/ B o.S. N AN E/ t 9 /e www w a s 9 9 4 4 599 2 3 W iii W d Nov. 21, 1933. c,D, RUBEL 1,935,819

PNEUMATICI FLUID ELEVATING DEVICE Nov. 2l, 1933. c. D, RUBEL PNEUuA'rIcFLUID ELEVATING DEVICE Filed June 12. 1930 5 Sheets-Sheet 5 1 ;:5....|l||.|||||.ll

:INVENT 25A T ToRNEYs.

Patented Nov. `21, 1933 UNITED STATES PATENT OFFICE This inventionrelates to pumping means for oil and water wells. It has particularreference to a pneumatic pump which isv operative to elevate-fluid fromany depth o f well and in which the operationris entirely automatic. Aswill be apparent, either air or natural gas ora mixture of the two, orindeed substantially any other gasecus` medium, can be used as thepressure medium to operate the pump; mostly for conciseness Ihereinafter referto this pressure medium as air or gas.

It is well known to those skilled in this art that in drilled wells,such as oilwells, the entire pump mechanism must be coniined within arelatively small diameter because of the limitations imposed by thediameters of the wells. Furthermore, deep .Wells require the use ofconsiderable pressures.

The primary object of my invention is to provide a novel and improvedform of pneumatic displacement pump meeting these and the otherconditions encountered in the pumping of wells, and particularly in thepumping of deep drilled Wells.`

Other and more speciflc achievements will be apparent from the matterwhich follows herein.

An important object is the provision of a method of controlling thevalve operation by the agency of alternately acting diiierentialpressures.`

Another important object is the provision in a pneumatic lift pump foroil wells, of means for creating and applying differential pressures al-Y ternately to opposite sides of an actuator element movable by reasonthereof.

This application is a continuation as to all common subject matter, ofmy prior application Serial Number 198,193 on Pneumatic displacementpumps, filed June 11, 1927, and my prior application Serial Number306,848, led September 19, 1928.

With the above noted objects in view and such others as will beapparentfrom the description, the invention resides in the novelconstruction, combination and arrangement of parts hereinafterillustrated and described. This specification and theaccompanying'drawings describe and illustrate a preferred, practical,physical embodiment of the principles of the invention, but it isobvious and it is intended that Vchanges may 50 be made by .Way ofmodification of structural details and the principles of the inventionmay be embodied in other forms without departing from the intent andscopeof the invention.'

Figurel is an elevation partly in section of an oil well installationhaving a pump constructed in Vaccordance with the principles of thisinvention.

Figure 2 is an elevation, partly in section, of an upper portion of oneof the pump units.

. Figure 3 is a vertical section through the intermediate portion of theunit, details of the operating mechanism being shown partly inperspective and with parts omitted for clearness.

Figure 4 is a similar view of the lower portion i of the unit.

, Figures 2, 3, and 4 taken together show the Vunit as in fillingcondition, with exhaust valve open and pressure inlet valve closed.

Figure 5 is a view similar to Figure 2, but in vertical section. Y

Figure 6 is a view similar to Figure 3, but in vertical section.

. Figure 7 is a view similar to Figure 4,'but in vertical section.

All of Figures 5, Sand l taken together show the mechanism in oilelevating position, the pressure exhaust valve being closed and thepressure inlet valve being opened.

Figures 8, 9 and l0 are sections, partly in elevation, Vtaken at arightV angle respectively to Figures 5, 6 and 7.

Figure 1l is a section, partially in perspective, of details omitted inFigures, 6 and 9, and at a right angle relative thereto.

Figure 12 is a section, mainly in perspective of details shown in Figurel0.-

Figure .13 is a horizontal section on the i3- 13 of Figure 11.V

Figure `14 is a horizontal section on the line 14-14 of Figure 11. 90

Figure l5 is a section, partly in elevation, of a detail. Y

Figure 16 is a vertical section of the pump of the preceding figures. Y

As shown in Figure l the pump is employed in connection with the usualstring of well casing l5 having a conventional casing head 16 havingoutlet pipes 17 for exhaust of the pneumatic pressure medium employed.The casing head receives therethrough inthe usual manner the dependingfluid discharge pipe line 18 which is line `led oi at the top of thewell and Whichline exof a general assembly which all forms of myinvention may take. Inasmuch as it is possible to operate my, pumpthrough the utilization of Bradenhead gas pressure, I have .illustratedin Figure 1 a means for bringing this about. This means comprises theusual installation of a Bradenhead casing 23 surrounding the usualcasing 15 and having an outlet line 24 controlled through a valve 25 forcommunication through pipe 26 withthe inlet supply line 20 to the pumps.It will be obvious that with the valve 2l closed and the valve 25 open,the pressure of the Bradenhead 23 is passed through the supply line 20to operate the pump, dispensing with the employment of externalpneumatic pressure and making the entire installation an automaticself-contained and self-operative unit. In such situations the exhaustpipe 68, hereinafter referred to, may be led up to and connected to theexhaust or outlet pipe 17. As will be apparent however, and as indicatedin the drawings, the pump can be operated by a pressure medium suppliedother- Wise than by the well itself.

The pump unit 27 as shown in Figure 'l is disposed at the bottom of thewell and consists of an elongated cylindrical pump chamber closed at itsbottom by a plug 28 provided with an oil inlet bore 29 communicatingwith the usual sand strainer 30, and which bore communicates vwith atubular nipple upstanding from the plug 28 a short distance into thebottom ,of the pump chamber and having attached -at its upper end a cage32 within which operates a ball check valve 33. l

Spaced above the top of the cage32 is a perforated strainer plate34`which is anchored in position by rigid connection with diametricallyopposed oil discharge pipes 35 which extendvertically upward Within thepump chamber being inchored at their upper endsin Va block 36, whichblock is formed with an internal passage 37 in communication with theopen ends of the pipes 35 and which passage communicates at 'its centralpoint with the bore 38 of an'externally threaded plug 39 through meansof which the block 36 is threaded into the lower end of a casting 40 tobe later described in detail. This casting 40 is formed with an VVoilconduit 4l in communication with the bore 38 so that oil is passedupwardly through the conduit 4l and through a passageway 42 provided inthe top pl'ug'or head 43 of the pump chamber. It will be observed (seeFigs. 4, 7j and l0) that a space is provided, at a lower level .than theoutlet vend of the oil inlet passage 29-3l, to receive any sand thatrnayenter the pump through the inletpassage; this is the space immediatelyabove the plug 28 within the bottom end of the pump casing,.and whichentirely surrounds the nipple 3l. ends of the oil discharge pipes 35, orrather the entrances into these pipes or into at least one of themyarelocated in thisspace and at Vsuch a point therein (e. g. so low) that.sand is prevented from accumulating on the floor or plug 28 of the pumpchamber to such a depth as to reach the outlets from the inlet passage'29 (the openings in the valve case 32) and overow onto the seat of thecheck valve 33. kUnless prevented, accumulation of sand at the bottom ofthe pump may prevent `the valve 33 for the liquidV inlet passage fromseating properly and thus impair the eficiency of the pump. Theplacement and arrangement of the discharge pipe'valve 49 prevents `theaccumulation of sand on the seat of this valve also, as will beapparent. v

Furthermore', the lower4 The head 43 is formed with a reduced neck 44which has attached thereto a vertical auxiliary chamber 45concentrically disposed relative to the main chamber of the pump unitand closed at its upper end by a plug 46. which plug is provided with acentral bore receiving therein the lower end of the air line pipe 22.

'Ihe oil discharge pipe line 18 extends downwardly through the pipe 22in concentrically spaced relation passiner through the plug 46 andassociated at its bottom with a chamber 47 within which is disposed acage 43 for a ball check valve 49 seated at the upper end of a tubularnipple 50 carried by aspider 5i arranged within the chamber '45 adjacentthe upper end thereof and which tubular nipple is'in communication withthe upper end oi an oil line section 52, which pipe section hascommunication at its lower end with the oil passage 42 in the head 43.The pipe 52 is concentrically arranged in spaced relation 'withinandrelative to the walls of the chamber 45.

Frorn'this description of the oil discharge line of the pump it isapparent that the discharge of oil from the pump chamber is from theextreme lower end of the chamber upwardly through rthe-oil line and pastthe check valve 49 to theoil discharge line 18, this check valve 49being arranged and disposed in the auxiliary chamber 45 above thechamber of the pump unit.

The pneumatic pressure medium which is pref- 1r ji-1,'

erably compressed air is supplied to the pump chamber through thepressure line 20 to the air pipeline 22 which carries the pump string byreason of its lattachment inV theplug 46. The

pneumatic pressure'medium in entering the pump j chamber passesdownwardly through the pipe 22 into the auxiliary chamber 45. The lowerend of the chamber 45 is closed by virtue oi its connection to the neck44 onthe pump head 4S, but

this head 43 is formed with an air passage 53 ex,-

relative to the valve seat by means ofinechanism to be later describedin detail.

In order to prevent the entrance or" loose scale, rust and otherforeignr matter into the main chamber of the pump, I provide within theauxiliary chamber 45 a vertical section of pipe 59 having kcommunicationat its lower end with theV air passage 53 of the pump head 43 and whichpipe isdisposed in parallel relation to the pipe 52 being formed at itsupper end in the shape of an annulus or ring 60 which surrounds the pipe5,2 and which portion 60 is provided on its under surface With ports 6lby which air is admitted tothe pipe section .'39 and consequently passesdownwardly through the air passage connections previously describedentering through the Aopen pressure inlet valve 58 to theV interior ofYthe-main pump` chamber above rthe body of liquid vwhich is disposedtherein in thelling cycle of the pump.

V The pneumatic pressure medium is exhausted i411* fromthe main pumpchamber at the'upper end thereof when the'exhaust needle valve 62 isopen. Whenthisvalve 62, which is .vertically movable relative to itsseat 63, is opened, the pneumatic pressure medium exhausts through thespace 64 and through the valve yseat bore 65 into a chamber 66 formedinthe pumprhead 43, which chamber is in communication with a radial orlateral exhaust passage 67 leading therefrom to a vertical exhaust pipe68y which extends upwardly on the pump head 43 in parallel relation tothe Walls of the chamber 45 so vthat the pressure of the exhaustingpneumatic medium will be directed upwardly .of the pump casing thuseliminating any back pressuredue to lateral exhaust.` y

VIn this type of' pump in the operating cycle the pump chamber isallowedto fill with oil which in ascending within the pump chamberoperates a member which moves Vat 'a certain point to close the pressureexhaust valve and open the pressure inlet valve. The pneumatic pressuremedium then operates against the surface of the oil to force the samefrom the pump chamber through the oil discharge line to the top of theWelland when the levelV of liquid within the pump chamber reaches acertain point the combination of forces actinglin the manner to be laterexplained in detail, operates to change the valves so that 'the exhaustvalve is opened and the pressure inlet valve is closed, thus permittingthe pump chamber to refill with oil from the well. The means by whichthe valves are operated constitute a feature of this invention and thisvalve operating means and mechanism will now be described in detail.

In the lower part of the pump chamber are provided at vertically spacedintervals a series of annular guides 69 which are rigidly attached tothe respective oil discharge pipes 35, which guides are centrally boredto receive' therethrough in slidable relation a float/which has theform` of an elongated cylindrical shell 70,

Y which shell as best shown in FiguresV 4 and '7,

has its lower end partially closed by an end plug low centrallyupstandingneck 73 which receives therein the guide pin74 of a hollowcylindrical mandrel '75 which mandrel has an overall lengthsubstantiallythreequarters the length of the shell within which it ispositioned. YThe mandrel 75 is rigidly mounted within the pump chamberby means of a standard '76 extending downwardly )from the bottom ofthe'mandrel andrpassing freely through the aperture 72 in the bottomplug 71 of the shell. The bottoni of the standard is providedv with alaterallyk enlarged foot portion 77 which is anchored to the strainerplate 34 by suitable means, which-in the presentinstance comprises asecuring cap Iv78 which cngages over the footl portion 77 and which isrigidly attached to the strainer plate. As previously explained,` thestrainer plate 34 is rigidly mounted within the pump chamber by reasonof its connection with the oil discharge pipes 35.

Accordingly by reason of therattachment of the tween the walls Vof theshell and the mandrel,

theshell being at all timesrcentered relative to the mandrel by reasonof the guiding engagement of the mandrel pin 74 within the shellneck 73.

Anchored to the top of the shell neck 73 is a collar 79 to which ispivoted at opposed points a pair of vlink levers 8G and 8l. These linklevers 30 and 81 extend vertically upwardly and outwardly relative tothe collar '79 and have pivotal connection at their upper ends with apair of cross levers 82 and 83 respectively, which cross levers arepivoted intermediate their ends on opposite sides of a centrallydisposed mounting block 8e from the opposite side faces of which arepivotally suspended stirrups 85 and 86. The cross lever 83 is pivotedintermediate its endsto the lower end of the stirrup 85, while the crosslever 82 at the opposite side of the block is pivoted intermediate itsends to the lower end of the stirrup 86.

The opposite ends of the cross levers 82 and S3 are respectively pivotedto iixed fulcrum points S7 and 8S respectively which fulcrum points aredisposed at the lower Yends of anchor rods 89 and 99 depending inparallel spaced relation from the casting 49, to which casting the upperends of the anchor rods 89 and 90 are rigidly attached.

The stirrup mounting Vblock is held in position by reason oi a rigidconnection with `the lowerends of four vertical rods 9l, 92, 93 and 94which extend upwardly from the mounting block in parallel spacedrelation passing freely through bores provided for that purpose in thecasting 40 and which extend'upwardly within the pump chamber to within ashort distance below the head plug 43 thereof, as best shown in Figures2 5. l

The upper ends of these rods 91, 92, 93 and 94 terminate in a commonhorizontal plane and have attached thereto a bearing plate 95, whichplate is centrally apertured with a bore 96 to perpassage therethroughof elements to be later plate 97 centrally apertured as at 99 to permitl vertical reciprocaticn therethrough of the stem of the needle valve 58which controls inlet of the pneumatic pressure medium to the pumpchamber.

By reason of this construction it will be apparent that as the shell 70reciprocates vertically with respect to the mandrel 75, there will be acorresponding reciprocatlon of the push rods 91, 92, 93 and 94 with aconMouent vertical reciprocation of the hearing plate 95 and the spiderplate i 97 with its cylinder 98, which cylinder functions as a buffer,or baiile meen for thepressure medium when the pres 'ire in tvalve open.

The speciiic valve mechanism comprises a vertically elongatedVhollowtube 190 which passes in freely slid/tele relation through thebore 96 of the bearing plate 95, having rigidly secured in its upper enda plug 191 formed with a peripheral flange 102 and which provided with acentral bore through which is slidaioly disposed the stem 62 of theexhaust needle valve. The needle valve 62 has at the bottoni of its stema head 193 which moves within the tube lilo being normally urged tovalve stern projected position by theaction of an expansion spring 104which is housed with,-

passes through a bore provided for that purpose' in the valve lockmember 108 and the valve stem is provided within the-tube 100 with ahead 108 which cooperates with the partition 105 to receive therebetweenanv expansion spring 109 which normally acts against the head 108tomaintain the needle valve 58 into projected position relative to thetube 100. f

The casting 40 is substantially in the form of a cylindrical plug memberand parallel spaced webs 112 with a plate 111 at their tops, as bestillustrated in Figure 1l, and it is anchored relative tothe pump chamberby a connection with the pump chamber head 43. The pump head 43 hasrigidly attached to the under face thereof by means of the securingbolts 110 the plate 111, which plate functions as a supporting base `forthe pressure exhaust valve seat 63. This plate 111 is in connection withthe casting 40 by means of the diametrically opposed parallel spacedwebs 112, which webs are preferably formed integral with the casting 40and the head lllvso that the elements 10,y 111 and 112 may be casttogether as a unit. These webs 112 are sufiiciently thick in crosssection to provide for the formation therethrough of the respectivebores 4l and 54, forming respectively the oil discharge line passage andpressure medium inlet passage previously described and they may serve asguides for the lvalve mechanism, e. g. specically, the plates 95 and 97as illustrated in Fig. 1l. The casting 40 on opposite sides of the websections 112 is provided with vertical-bores through which therespective push rods reviously described and valve lock operating rodsare-disposed for freely slidable movement.

Surrounding the upper portion of the valve tube 100 between the top faceof the bearing plate 95 and the flange 102 of the plug 101 isarranged acoiled expansion spring 113, its respective-ends abutting the bearingplate and the flange. In a similar manner a relatively heavy coiledexpansion spring 114 surrounds the tube 100 between the bottom face oi'the bearing plate 95 and a peripheral flange 115 provided for thepurpose on the valve lool; member 106, respective ends of this spring114 abutting the bearing plate 95 and the flange 115.

Adjacent the laterally enlarged head 107 of `the valve locking member106 and spaced vertically on opposite sides thereof so as to be aboveand below the valve locking member, the webs 112 are formed withV ears116 which are positioned to receive the pivot pins of four bell cranklevers arranged in sets of pairs, one set comprising the pair of levers117being arranged above the valve lock head 107 and the other setcomprising the pair of levers 118 being disposed below the valve-lockhead 107. The disposition of n these bell crank levers is such that in acertain position of the mechanism that is when the pressure inlet valve,is open, as shown in Figure 6, the` inner ends of the levers 118 will beprojected beneath the lock head 107 to maintain the same in raisedposition. With the pressure inlet valve in closed position the partswill assume the positions as shown in Figure 3 with the inner ends ofthe upper levers '117 engaged-against the top face of. the lock head107, while the lower leversl 11,8 will have been freed ofv theirengagement against the under face of the lock head. In order toeliminate friction the respective inner ends of the bell crank leversare provided with rollers for cooperating with the inclined vfaces ofthe Vlocking head 107.

The means for-actuating the bell crank levers will not be described indetail. Pivoted to the lever 83 intermediate its` xed fulcrum point 88and its connection with thestirrup 85 is a vertically upstanding valvelock operating rod 119 which extends through a bore provided in thecasting 40 for that purpose and which terminates at its upper endadjacent the spring bearing plate 95 at the top of the pump chamber.Similarly fromvthe lever 82 there extends upwardly a second valve lockoperating rod 120 which passes through the casting 40 on the oppositeside and extends in parallel relation to the rod 119. Adjacent theirupper ends these rods are guidedv by a cross arm 121 Aformed on the websections 112.

Adjacent the valve lock element 106 the rod 119 is provided with athreaded portion 122 and in similar manner the rod 120 is provided witha threaded portion 123. Threaded over these respective threaded portionsof the valve lock operating rods are respectively upper and loweradjusting nuts 124and 125. These nuts cooperate with slidable actuatorelements 126 and 127 which are freely movable with respect to the rods119 and 120. The outer ends of the bell crank levers 117 and 118 arerespectively bifurcated toA engage the respective push rods therebetweenin freely slidable relation and in the case of theupper bell cranklevers 117 slidable stant engagement with vthe bifurcated ends of therespective levers 118 through the agencyof expansion springs 130 whichsurround the rods 119 and 120 between theupper face of the casting 40and the said actuators 129. Likewise, the actuator elements 128 areurged intov constant engagement with the bifurcated ends of the levers117 through the agency' of coiled expansion rsprings131 which surroundthe rods 1 19 and 120 between the elements `128.and' the cross arm guide121.1 It is obvious that by an adjustment of the nuts 124 and 125 ontheir respective rods, the vertical-spacing of the actuator elements 126and 127 may be set atany desired adjustment.

This adjustment determines the timing ofthe valve operation and is animportant feature of the present invention.

In the operation of the pump, assuming the parts to be inthe position asshown in Figures 2, 3 and 4 with the exhaust valve 62 open and thepressure inlet valve closed, the purnp4 chamber will ll from the bottomwith oil passingv in through the strainer plug30 and rising through thecheck valve 33. The oilcontinues to pass upwardly'within the pumpchamber and as it rises past the strainer plate 34 above the bottom ofthe shell 70 a certainy amount of air and gas given off from thesurfaceof the rising oil will opening 72. As the oil continues torisethe air and gas within the shell is compressed within.

the shell imparting a denite buoyancy thereto, the lifting action ofwhich is assisted by the coiled spring 114 acting betweenthe plate 95and the flange 115, and is resisted by compression of the spring 113acting against the upper face of the spring bearing plate 95 which isArigidly secured to the upper ends of the push rods 91, 92, 93 and 94.At this point it should be explained that under the buoyancy imparted bythe trapped air Within the shell, upward movement of the shell forcesthe links and 81 upwardly and outwardly to rock the cross levers 82 and83 upwardly with respect to their fixed fulcrumsr87 and 88. At the sametime through the medium of the stirrups 85, the elevating movement ofthe cross levers 82 and 83 is transmitted to the supporting block 84,which through its rigid connection with the push rods 91,V 92, 93 and 94causes these rods to lift, thereby lifting the spring bearing plate 95against compression of the spring 113. v

Inasmuch as the ilange 102 on the plug 101 is maintained at this stagein a xed position by virtue of its rigid connection with the valve tube100, it is obvious that' at some point in the continued upward movementof the shell acting as a iloat, the force of the spring 113 willneutralize the buoyancy of the shell and arrest the movement of theparts. This is true by reason of the fact that the lock head 107 isrigidly connected with the lower end of the tube 100 and is preventedfrom rising by the locking action of the upper levers 116 which aremounted on the casting webs 112 and through the medium of the rigidsupport afforded by these casting webs, it is obvious that the lockinglevers can move only to rock on their pivots. However, this check isovercome by the hydrostatic pressure of the liquid column surroundingthe shell 70, acting cumulatively with the buoyancy. Due to the mandrel,a'definite volume of oil is displaced within the shell, so that eventhough their levelsv f' ment of` the rods 119 and 120 these-actuators125 will engage under the bifurcated ends of the levers 116, rocking thesame upon their pivots so that they will be released from engagementwith the lock head 107 and will assume the position as shown in Figure6. f

At the instant of this occurrence, under the expansive action of thespring 113 combined with the motive force ofvthe shell 70, the valvetube 100 will be snapped upwardly to close the pressure exhaust valve 62against its seat 63 and at the same time the lift thus imparted to thelock member 106acting against the head 168 of the needle valve 58, willlift valve 58 from its seat 56 and thereby permit entry of the pneumaticpresf L sure medium to the interior of the pump chamber.

As this pneumatic pressure medium is under considerable pressure it isnecessary to provide a means for retarding the initial entry into thepump chamber in order to prevent a too rapid building up lofpressure'therein. This means is provided in the cylinder 98 as airentering through the 'open pressure inlet valveexpandsv withintheeylinder acting upwardly against the plate 97 .whereby the expansiveforce is resisted by the downward pull exerted on this `plate 97 by theweight of the elementswhich-are suspended therefrom. by` reason` of itskconnection with the rods 91, 92, 93 and 94. Consequently, the airpressure is passed at a reduced rate from the cylinder 98 to theinterior ofthe pump chamberabove the surface of the oil conned thereinbythe closingof the ball check valve 33.V

In this action of the mechanism downward movement of the lock head 107is arrested by the engagement thereunder of the lock levers 118 and theair pressure builds up within the pump chamber' to force the oilcontained therein upwardly throughthe oil discharge pipes 3,5, Dassages37 and 38, and passage 41 in the web sec-v tion 112 upwardly through thepassage 42 in the pump head 43 to the pipeI 52 from whence itpassesfthrough the check valve 49 into the oil discharge line 18. i

- During the filling cycle of the pump chamber a lcertain amountof oilwill have entered the shell 70 rising upwardly therein in the clearancespace provided between the -walls of the shell and the *mandrelv 75.Consequently although at the time of admitting the pressure medium theoil level externally of the shell 70 will be higher` than the oil levelwithin the shellVwh'en the oil descends under the action of the pressuremedium it will descend at a-greater vrate of speed externally oftheshell 70 thanI within the shell due to the fact that the pneumaticpressure acting on the surface of the oil is greater than the expansiveforce exerted by the air and gas which is trapped in theupper portion ofthe shell 70.

As the oil continues to be ejected from, the pump chamber the levelexternally of the shell 70 decreases Vrapidly and ultimately reaches apoint at which the surface of the oil externally of the shell 70 isconsiderably below the level of the yoil within the shell. It -will beunderstood that at onestage the oil level both within and without theshell 70 will be at Ythe same point and the pressures will therefore beequal. However, as the oil externally kof the shell 70 drops below theoil level within .the shell, the downward pressure or forceexertedagainst the shell 70 overbalances buoyant force imparted thereto byreason of the pressure acting against the surface of the oil externally0fA the shell. A diierential pressure is4 thus created which causes adownward movement of the shell 70 with considerable force thus drawingdown the links 80 and 8l and rocking the cross levers 82 and 83downwardly thereby exerting a `pull on the stirrups 85 which pull istransmitted'through the block 84 to the rods 91, 92, 93 and 94. Thisdownward pull is in turn transmitted through these rods to the springbearing plate 95 and this plate tends to move downwardly againstcompression of the `spring 114 which surrounds the valve tube 100between the plate 495 and the spring bearing nange 115 of the lockelement 106. As the lock element is positively arrested by :engagementof the levers 118 beneath the lock head 107, it is apparent that thedownward movement of the elements just described will be againstcompression of the spring 114. f

As the downward movement of. the elements just described continues Ytherods'119. and 120 will have been correspondingly drawnY down and at acertain Apoint the actuatorelements 12'7 will engage the bifurcated endsof the'bell crankof oil whichrfills through the strainer plug 30 asA in`theinitiallling cycle. The passage provided for exhausting thepneumatic pressure medium has already been described in detail.

dium trappedvwithin the shell 70 may be lost by entering into solutionor suspension in the oil, it may be necessary from time to time toreplenish this supply without building up too great a pressure withinthe shell. This iseiiected by the provision of the mechanism shown indetail in Figure 15. This means comprises a vertical pipe 132 which isVarranged externally of the shell '70 in parallel relation Y therewithbeing passed through the guides 69. At its lower end the pipe islaterally inturned and connects into the lower portion of the standard76 which carries the mandrel '75. yAt this point the pipe is in opencommunication with a conduit or passageway 133 Awhich is formedthroughout substantially the entire length` of the standard '76 andwhich opens adjacent the upper end of the standard into the shell 70 asbest illustratedin Figure '7. At its upper end, which is disposed lat apoint above the highest possible liquid level within the pump chamber,.the pipe 132 is capped as at 134, which cap supports a cage member 1735containing a plurality of serially arranged ball check valves 136.Adjacent the bottom of the cage or support 135 a port 137 is providedfor communication to chamber during the exhausting cycle thereof, if

the pressure within the shell '70 is too low, the

check valves 136 will be opened, permitting a building up of pressurewithin the lshelltothe desired point. When this point has been reachedthe check valves 136 will of course automatically close and will notreopen until Ypressure within the shell has dropped below the desiredpoint.

Regardless of the correctness ofthe theory of the operation of thehollow float Yand'mandrel combination described above, the fact remainsthat such a combination will serve to operate the valve mechanism toadmit and exhaust the pressure medium, and as will be apparent a hollowoat open at or near its bottom has a desirable characteristic overentirely closed hollow floats, particularly Where the air pressures arevery high, in that the internal and external pressures on the former aresubstantially equal at substantially all times, and the mandrel seems toenable agiven pump having an open hollow float to deliver a greateramount of oil per stroke than were it omitted. It' is apparent too ofcourse that valve mechanismsof the type described above are notk oatwith -mandrel combination, valve mechanisms of this type ,can be usedwith other float constructions where other iloat constructions areusable under the conditions encountered.

I claim:

l. In a pneumatically operated liquid lift pump having alternatelyacting pressure valve means, the method of operating the valve meanswhich consists in periodically-applying to said valve means differentialpressures applied in opposite directions.

2. In a pneumatically operated liquid lift pump having alternatelyacting pressure inlet and exhaust/valves, meansfor operating saidvalves, said means including a member positively actu- Vated in oneYdirection by hydraulic pressure and As a certain percentage of thepressureme- Y in an opposite direction by pneumatic pressure.

3. In a pneumatically operated liquid lift pump having alternatelyacting pressure supply and exhaust valves, means for operating saidvalves, said means including an actuator connected to said-valves toactuate the same'and having a surface acted upon by pneumatic pressurefor positive movement of the actuator in one direction, and saidactuator having a portion acted upon by hydraulic pressure for positivemovement of the actuator in an opposite direction.

4. In a pneumatic pressure Yfluid pump, a pres-- sure inlet valve, apressure exhaust valve, actuator .means movable to operate said valves,said actuator means having a portion responsive to pressure variationeiected by differential fluid levelswithin the pump whereby to move saidactuator means, and means for effecting and maintaining a changeabledifferential iiuid level within the pump. Y

5. In a pneumatically operated liquid lift pump, valve means controllingthe pressure supply and exhaust, actuator means adjacent thereto foroperating said valve means, said actuator means including a plurality ofconnected members arranged for relatively slidable movement, Vlatchmeans for holding one'member in a set position, said one member beingconnected to said valve means to actuate the latter, means on another ofthe members for 'tripping said latch means, and a float in the liquid tobe pumped controlling said another of the members.

6. In a pneumatically operated liquid lift pump, valve means controllingthe pressure supply and exhaust, actuator means for operating said valvemeans, said actuator means including a xed liquid displacing member, asubstantially tubular member, connected to said valve means to actuatethe same, open at-one end and disposed over said displacement member inlfreely slidable relation and said 'tubular member and displacementmember being adapted forl operation while emersed in liquid lifted bythe pump.

'7. A pneumatically operated liquid lift pump comprising a chamberhaving liquid inlet and liquid outlet means, means for supplying apneumatic pressure medium to said chamber, means for exhaustingpneumatic pressure medium from said chamber, alternately acting valvemeans controlling the pressure medium inlet and exhaust, anY actuator insaid chamber and movable in one direction therein by hydrostaticpressure of ator is controlled by the volume of liquid within the pumpchamber.

8. In a pneumatically operated-oil well pump, the combination with thevalve mechanism controlling the supply and exhaust of thepressuremedium, of means for actuating said valve mechanism in one directionunder the iniluence of hydrostatic pressure, means for operating saidValve mechanism `in an opposite direction-under the influenceofpneumatic pressure, and means whereby the application of said pressuresis automatically controlled by the volume of liquid within the pumpchamber.

9. In a pneumatically operated liquid lift pump,

the method of controlling the supply and exhaust of the pneumaticpressure medium which consists in effecting a differential pressurewithin the pump by directional `movement of the liquid within the pump,and employing such differential pressure to set into operation powermeans controlling the supply and exhaust of the pressure medium.

10. An actuator element forpneumatically operated liquid lift pumps,comprising a xed liquid displacement member, alhollow cylindrical shellopen at one end and disposed over said displacement member in verticallyslidablerelation thereto,and means carried by the closed end or saidshell for operating valve mechanism with which the pump may be provided.

l1. In a pneumatically operated liquid lift pump, the combination withthe pump chamber and pressure valve mechanism thereof, of a hollowsubstantially cylindrical member vertically Vslidable within said' pumpchamber and adapted for movement with its lower end disposed beneath thesurface of liquid in the pump chamber, the Vbottom end of saidcylindrical member being provided with an opening for the trappingthere- 1n of air, and a liquid displacement'body disposed within saidcylindrical member and having a iixed connectionwith the pump chamberwhereby to` cause a diiere'ntial pressure to exist on said cylindrlcalmemberwithin the pump chamber, and

operating connection between the upper end of said cylindrical memberand the valve mechanism of the pump. l a

12. In a pneumatically operated liquid lift pump having alternatelyacting pressure valveY means, the method of operating said valve meansYwhich consists in employing differential pressures, periodically appliedto said valve means in opposite directions, to produce power for op-Verating said valve means, and controlling the periodicity by liquidlevels within the pump.

13. The method of operating valves in pneumatic liquid lift pumps whichconsists in applying thereto power derived from an unbalance created byadding hydrostatic pressure of liquid in the pump to pressure of thepneumatic pres-` sure medium. f v

14, In aV pneumatically operated elongated liquid lift pump adapted to Vbe operated in a substantially vertical'position, means providing anelongated pump chamber and a liquid discharge passage leading from saidchamber, valve means level,characterized'v by the fact that at least oneof said rod-like members is hollow and provides a lower portion of saidliquid discharge passage.

15. In a pneumatically operated elongated liquid lift pump adapted to beoperated in a substantially vertical position, means providing anelongated pump chamber and a liquid discharge passage leading from saidVchamber, valve means controlling the entrance of gas under pressure intothe pump chamber to discharge liquid therefrom and controlling theexhaust of gas from the chamber, a iloat within the chamber operable by`the liquid therein to actuate said valve means, and a plurality ofrod-like members extending substantially longitudinally of and Withinsaid chamber and external of said oat, to guide the float` as the latterrises and falls with the liquid level, characterized by the Vfactthatguide members for the float, to engage and more or less encircle thefloat, are mounted on said rod-like members.

16. In a pneumatically operated liquid lift pump, means providing a pumpchamber anda liquid discharge passage leading from said chamber, valvemeans controlling the entrance of gas vunder pressure into the pumpchamber to discharge liquid therefrom, spring means to operate saidvalve means, a member at the chamber operable by the liquid therein toput said spring means under valve-operating tension, latch means toprevent operation of said valve means by said spring means undervalve-operating tension, and means to operate said latch means torelease said valve means to permit operation of said valve means by saidtensioned spring means.

17. In a pneumatically operated liquid lift pump, means providing a pumpchamber and a liquid discharge passage leading vfrom said chamber, valvemeans controlling the exhaust of gas from the pump chamber, spring meansto operate said valvel means, a member at the chamber operable by theliquid therein to put said spring means under Valve-operating tension,latch means-to prevent operation of said valvemeans by said spring meansunder valve-operating tension, and means to operate said latch means torelease said valve means to permit operation of said valve means by saidtensioned spring means.

18. In a pneumatically operated liquid lift pump, means providing apump' chamber and a liquid discharge passage leading from said chamber,valve means controlling the entrance of gas under pressure into the pumpchamber to discharge liquid therefrom and controlling the exhaust of gasfrom the pump chamber, spring means to operate said valve means, amember at the chamber operable by the liquid therein to put said springmeans under valve-operating tension, latch means to prevent operation ofsaid valve .eans by said spring means under valve-operating tension, andmeans to operate said latch means to release said valve means to permitoperation of said valve means by saidtensioned spring means.

19. The subject of matter or" claim 16, characterized by the fact thatsaid member is a float.

20. The subject matter of claim 17, characterized by the fact that saidmember is a iloat.

2l. The subject matter of claim 18, characterized by the fact that saidmember is a float mounted within the pump chamber. f

22. In a pneumatically operated liquid lift pump, means providing a pumpchamber and a liquid discharge passage leading from said chamber, valvemeans controlling gas under pressure for forcing lliquid from saidchamber through said liquiddischarge passage, a hollow iioat within thechamber controlling the operation of said valve means, the interior ofsaid float being open to the chamber, anda member occupying a portion ofthe space Within the float.

23. The subject matter of claim 22, characterized by the fact that saidmember occupies a portion of the space within the float that otherwisewould be reached by liquid. Y

24. The subject matter of claim 22, characterized by the fact that saidmember occupies 'a portion of the space within the oat thatV otherwisewould be reached by liquid, and by the fact that said member is fixed inposition with respect to the pump chamber.

25. In a pneumatically operated liquid lift pump, means providing a pumpchamber and a liquid discharge passage leading from said chamber, valvemeans controlling gas under pressure for forcing liquid from saidchamberr through said Vliquid discharge passage, a iioat within the pumpchamber to control the operation of said valve means, said float havingthe form of a downwardly open shell, and amember occupying a portion ofthe space within said shell.

26. The subject matter of claim 25, characterized by the fact that saidmember occupies a portion of the space within the shell above theopening thereinto, and by the fact that said inember is relatively xedin position with respect to the pump chamber.

27. In a pneumatic displacement pump, the

combination with means providing a pump chamber having gas inletandexhaust ports and a liquid inlet port, means for supplying gas underpressure to said gas inlet port to expel the liquid, means providing aliquid-discharge passage leading from the lower portion of the pumpchamber, valve means controlling said inlet and exhaust ports, and meanscontrolled by the liquid to be pumped to control the actuation of saidvalve means, of a baiile for the gas under pressure entering the pumpchamber through said gas inlet port.

28. The subject matter of claim 27, characterized by the fact that saidbaille is a cylinder located at and receiving the gas from said gasinlet port.

29. In a pneumatic displacement pump, the combination with meansproviding a pump chamber having gas inlet and exhaust ports and a liquidinlet port, means for supplying gas under pressure to said gas inletport toexpel the liquid,

means providing a liquid-discharge passage leading from the lowerportion of the punjip chamber, valve means controlling said inlet andexhaust ports, and means responsive to the rise and fall of the liquidto be pumped to control the actuation of said valve means, oi a springtending to move said liquid-responsive means in one direction.

30. The subject matter offclaim 29, characterized by the fact thatVVsaid spring tends to move the liquid-responsive means in the samedirection as a rise of the liquid to be pumped.

31. In a pneumatic displacement pump, the

- combination with means providing a pump chamber having gas inlet andexhaust ports and a j liquid inlet port, means for supplying gas undervalve means controlling said inlet and exhaust ports, latch meanstending to hold-at least one of said valve means in one of itspositions, and etv oat in the liquid to `be pumped to release said latchmeans, of a spring to assist the liquid to raise the float.v

32. In a pneumatic displacement pump, the combination with meansproviding a pump chamber having gas inlet and exhaust ports and a liquidinlet port, means for supplying gas under pressure to said gas inletport to expel the liquid, means providing a liquid-discharge passageleading from the lower portion of the pump chamber, valve meanscontrolling said inletfand exhaust ports, latch means tending to holdsaid valve means for said gas inlet port in passage-Way closed position,and means responsive to the liquid to be pumped to release said latch,of

. means to, assist the movement of said liquidresponsive means in thedirection which brings about release of the latch.

33. In a pneumatic displacement pump, the combination with -meansproviding a pump chamber having gas inlet and exhaust ports and a liquidinlet port, means for supplying gas under pressure to said gas inletport to expel the liquid, means providing a liquid-discharge passageleading from the lower portion of the pump chamber, valve meanscontrolling said inlet and exhaust ports, latch means tending to holdsaid valve means for said gas inlet port in passage-Way closed position,and a oatin the liquid Within the chamber to release-said laatch meansas said liquid raises the float, of means tending to assist the liquidto raise the float.

, 34. The subject matter of claim 33, characterized by the fact thatVthe last mentioned means is a spring.v f

35. In a pneumatic displacement pump, the combination of means providinga pump chamber having gas inlet and exhaust ports and a. liquid inletport, means for supplying gas under pressure to said gas inlet port toexpel the liquid, means providing a liquid-discharge passage leadingfrom the lower portion of the pump chamber,

valve means controlling said inlet and exhaust ports, latch means actingdirectly on said valve means to hold said valve means in a positionwherein the passageway through said gas inlet port is closed and thepassage-Way through said exhaust port is open and also to hold saidvalve means in its opposite position wherein the passage-way'throughsaid gas inlet port is open and the passage-way through said exhaustport is closed, and a structure including a single member free tobeactuated by the rise and fall of the liquid to be pumped to actuate saidvalve means to both of its said positions, characterized by the factthat said latch means are located in the path of movement of saidstructure for control thereby.

36. In a pneumatic displacement pump, the combination of means providinga pump chamber having gas inlet and exhaust ports and a liquid inletport, means for supplying 'gas under pressure to said gas inlet port toexpel the liquid, means providing a liquiddischarge passage leadingfrom-the lower portion of the pump chamber, valve means controlling saidinlet and exhaust ports, latch means acting directly on said valve meansto hold said valve means in a position wherein the passage-Way throughsaid gas inlet port is closed and the passage-Way through said exhaustport is open and also to hold said valve means in its oppositepositionvwherein the passage-wayv through said gas inlet Vport is openand the passage-way through said exhaust port iskclosedand a structureincluding a float in the liquid within the chamber, free to rise andfall as the liquid level within the pump chamber rises and falls, toactuate said valve means to both of its said positions, characterized bythe fact that said latch means are located in the path of movementl ofsaid structure for control thereby.

37. The subject matterof claim 35, characterized by the fact that aspring means is interposed between said single member and said valvemeans, through which said single member actuates said valve means toboth positions of the latter. 1

38. In a pneumatic displacement pump, a hollow elongated memberproviding the pump chamber and having an inlet for the liquid to bepumped, means providing a discharge passage for the liquid leading fromthe bottom portion of the chamber, a pair of spaced heads at the upperportion of the chamber, a web connecting the two heads, a seat for a gasinlet valve at one of said' heads, a seat for a gas exhaust valve at theother of said heads, inlet and exhaust valve supporting means betweensaid heads, and means below the lower of said heads, actuatable by theliquid to be pumped, to actuate the valve.

39. In a pneumatic displacement pump, a hollow elongated memberproviding the pump chamber and having an inlet for the liquid to bepumped, means providing a discharge passage for the liquid leading fromthe bottom portion of the chamber, a pair of spaced heads at the upperportion of the chamber, a web connecting the two heads, a seat for a gasinlet valve at one of said heads, a seat for a gas exhaust valve at theothervof said heads, said seats facing in opposite directions, inlet andexhaust valves, a member between said heads carrying said valves, andmeansA below the lower of said heads, actuatable by the liquid to bepumped, to actuate the valves.

40. In a pneumatic displacement pump, a hollow elongated memberproviding a pump chamber and having an inlet for the liquid to bepumped, means providing a discharge passage for the liquid leading fromthe bottom. portion of the chamber, va pair of spaced heads at the upperportion of the chamber, a plurality of spaced webs connecting the twoheads, a seat for a gas inlet valve at one of said heads, a seat for agas exhaust valve at the other of said heads, gas inlet and exhaustvalves, a reciprocating structure carrying said valves and guided bysaid webs and means below the lower head, actuatable by the liquid to bepumped, to reciprocate said structure.

41. In a pneumatically operated liquidv lift pump, means'providing apump chamber anda liquiddischarge passage leading from said chamber,valve means controlling the entrance of gas under pressure into the pumpchamber to discharge liquid therefrom, means acting on said valve meanstending to operate the same, While liquid is discharging from thechamber and in which energy can be stored to operate said valve means, amember at the chamber, operable by the liquid therein, to store energyin said valveoperating means, latch means to prevent the operation ofsaid valve means by said valve-operating means during theliquid-discharging period, and means to operate said latch means torelease said valve means to permitA operation of the latter by saidvalve-operating means.

42. In' a pneumatically operated liquid lift pump, means providing apumpchamber and a liquid discharge passage leading from said chamber,valve means controlling the exhaust of gas from the pump chamber, meansacting on said valve means, tending to operate the same, while liquid isentering the chamber and in which energy can be stored to operate saidvalve means, a member at the chamber, operable by the liquid therein, tostore energy in said valve-operating means, latch means to prevent theoperation of said valve means by said valve-operating means duringthe-liquidV entering period, and means to operate said latch means torelease said Vvalve means to permit operation of the latter bysaidvalve-operating 'means.

43. In a pneumatically operated liquid lift pump, means providing a pumpchamber and a liquid discharge passage leading from said chamber, valvemeans to control the entrance of gas under pressure into the pumpchamber to discharge liquid therefrom and to control the exhaust of gasfrom the pump chamber, means acting on said valve means, tending tooperate the same, during the period in which the liquid is entering thechamber and in which energy can be stored to operate said valve means, amember at the chamber, operable by the liquid therein, to store energyin said valve-operating means, latch means to prevent the operation ofsaid valve `means by said valve-operating means during theliquid-entering period, and means to operate said latch means tovrelease said valve means to permit operation of the latter by saidvalve-operating means.

44. The subject matter of claim 4l, characterized by the fact that saidmember is a float, and by the fact that said means to operate the latchmeans Ais moved by said float. Y

45. The subject matterof claim 42, characterized by the fact that saidmember is a float, and by the fact that said means to operate the latchmeans is movedby said iloat.

46. The subjectpmatter. ol?` claim 43, characterized by the fact thatsaid member is afloat, and by the fact that said means to operate thelatch means is moved by said oat.

Y CHESTER D. RUBEL.

CERTIFICATE OF CORRECTION.

Patent No. 1,935,819. November 21, 1933.

CHESTER D. RUBEL.

It is hereby certified that error appears in the printed specificationof the above numbered patent requiring correction as follows: Page 2,line 39, for the syllabien an; page 4, line 85, tot' "not" read now;page 7, line 141, claim 19, strike out "of" first occurrence; page 8,line 106, claim 33, for "laateh" read latch; and that the said LettersPatent should be read with these corrections therein that the same mayconform to the record of the case in the Patent Qice.

Sinetl and seated this 9th day of January, A. D. 1934.

F. M. Hopkins (Seal) Acting Commissioner of Patents.

